
I have had bitches that I have never had spayed, bitches that have been spayed at around 2 yrs and 3 spayed at 6 months.
The ones spayed early were no different afterwards or years on to the ones spayed late or to the ones never spayed, except I have lost 2 unspayed girls over the years to problems that would not have arose had they been spayed, but temprement, coat or any other wise if anything I would say the spayed ones were all calmer and definatly more placid.
My advice would be to get her spayed if you don't wish to breed at a later time. Waiting, depending on the area you live in can mean confinement and restricted exercise during the season to try and stop unwanted attention from male dogs and maybe accidental mating. Only to end up with restricted exercise again for 10 days when you do have her spayed.